Chopper's Warning: 'You Are Paddleboarding Next to Approximately 15 Great White Sharks'

More than a dozen sharks were spotted just offshore in Southern California this week, drawing spectators to the beach in Long Beach and Orange County and prompting one epic warning from a sheriff's helicopter.

"Attention in the water, this is the Orange County Sheriff's Department ... You are paddleboarding next to approximately 15 great white sharks," a sheriff's deputy announces, as seen in video shot Wednesday afternoon in Dana Point. "They are advising you exit the water in a calm manner. The sharks are as close as the surfline. Thank you for your cooperation."

The department said sharks were seen in the water from Capistrano Beach to San Onofre. The sheriff's video showed sharks slowly swimming close to shore.

Sharks were also spotted near the Long Beach Peninsula at 4:30 p.m. Wednesday, and multiple sharks were spotted near the Alamitos Peninsula off the coast of Long Beach again Thursday morning.

On Thursday morning, Long Beach lifeguards confirmed there had been sightings, and that a shark advisory was in effect. No aggressive behavior was observed.

Lifeguards said the beaches were open Thursday, adding they have regular patrols and were monitoring the beaches closely.

The sightings come two weeks after a woman was bitten by a shark and critically injured in nearby San Onofre State Beach.

NewsChopper4 captured images of the sharks from the air days after 10 to 20 sharks were spotted Long Beach, prompting a shark advisory.

Advisory signs were posted throughout a 1.5-mile stretch of the beach where sharks were sighted, from Grenada Avenue to 72nd Place.

Safety officials said the 10-20 great whites came within 10 feet of the shoreline, but said the sharks have not shown aggressive behavior.

Chris Lowe of the Cal State Long Beach Shark Lab took an overnight boat ride to tag the sharks and track their every single movement.

"I've been doing this for 30 years," he said. "I never thought I'd see the day I'd have baby white sharks in my front yard."

Lowe is trying to figure out why there's such a large number of sharks so early in the year.

"Oceanographers are saying we might fall into another El Niño summer and that would be unusual, but this could all be related to climate change," he said.

Lowe estimated there were around 10 to 15 juvenile great whites off the Long Beach coast Wednesday night.